Change in internal engergy of a monatomic ideal gas

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SUMMARY

The discussion focuses on calculating the change in internal energy (\DeltaU) of a monatomic ideal gas expanding from 1.00 m³ to 2.50 m³ at a constant pressure of 2.00 x 105 Pa. The relevant equation for internal energy change is \DeltaU = Q + W, where work (W) is calculated as -P\DeltaV. The heat transfer (Q) is determined using the relationship Q = nCp\DeltaT, with Cp derived from the specific heat at constant volume (Cv) using the equation Cp = Cv + R. The solution was achieved by connecting these equations effectively.

PREREQUISITES
  • Understanding of the first law of thermodynamics
  • Familiarity with the ideal gas law
  • Knowledge of specific heat capacities (Cv and Cp)
  • Ability to perform basic thermodynamic calculations
NEXT STEPS
  • Study the derivation of the ideal gas law and its applications
  • Learn about the relationship between heat transfer and specific heat capacities
  • Explore the concept of work done by gases during expansion and compression
  • Investigate the implications of the first law of thermodynamics in various thermodynamic processes
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This discussion is beneficial for physics students, engineering students, and anyone studying thermodynamics, particularly those focusing on the behavior of ideal gases and internal energy calculations.

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Homework Statement


A monatomic ideal gas expands from 1.00 meters cubed to 2.50 meters cubed at a constant pressure of 2.00 x 10^5 Pa. Find the change in the internal energy of the gas.



Homework Equations



\DeltaU = Q + W

The Attempt at a Solution



Well, I know how to find work, which is -P\DeltaV

But I'm having trouble finding the energy transferred into the system by heat, or Q, because the problem does not give a specific value for it.

I would much appreciate it if someone could give me some pointers as to how to find Q.
 
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How is Q related the the specific heat at constant pressure?
 
I don't exactly know, I do know that \DeltaU = 3/2nR\DeltaT for a monatomic gas, where the molar specific heat is given by Cv = 3/2R
 
If you know CV, then Cp = CV + R. Also at constant pressure Q = n CpΔT. Now you can put it together.
 
Aha, thanks for the help! I got it.
 

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